Temperature Assisted Nucleation and Growth To Optimize Perovskite Morphology at Liquid Interface: A Study by Electrochemical Impedance Spectroscopy

In this work, methylammonium lead tri-iodide perovskite has been synthesized by spin coating of lead acetate trihydrate and methylammonium iodide precursor on preheated substrate. Significant difference in film morphology has been observed as the temperature was varied from room temperature to 120 °C prior to spin coating. Nucleation and growth mechanism is revisited to find out the optimum substrate temperature for fabricating uniform perovskite films and is attributed to the fast homogeneous nucleation followed by delayed growth process. Electrochemical impedance spectroscopy measurement at the perovskite–liquid electrolyte interface reveals the impact of film morphology on the anomalous diffusion behavior observed at the low frequency regime.